Hersent, Olivier. <br/><br/>
IP telephony :  deploying VoIP protocols and IMS infrastructure / 
Olivier Hersent. 
 - 2nd ed. 
 - Hoboken, NJ :  John Wiley & Sons,  2011. 
 - xxxiii, 439 p. :  ill. ;  24 cm. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>9780470665848 (hbk.)  RM275.40 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Internet telephony.<br/>Convergence (Telecommunication)